AD 76-16-07

76-16-07 CESSNA AVIATION: Amendment 39-2694. Applies to Cessna models 401 and 402 series airplanes and model 414 airplanes certificated in all categories, which have been modified in accordance with either Supplemental Type Certificate SA2424WE or SA117NW, incorporating Allison turboprop engines.

Compliance required as indicated.

To prevent and detect possible failures of the engine attachment tangs, of engine mount PN5002, accomplish the following:

(a) Within 10 hours' time in service after the effective date this AD, unless already accomplished, loosen the engine attach bolts and compress the rubber mounts. Use steel shims to reduce the gap between the forward tang and AN970 washer (with the bushing and washers compressed against the aft tang) to no greater than 0.005 inches and retorque the bolts to 160-190 inch pounds.

(b) Within 10 hours' time in service after the effective date of this AD, unless already accomplished, and thereafter at intervals not to exceed the time limits indicated below, visually inspect, with a glass of at least 8-power, the forward and aft tangs of all three engine attachment points on the engine support truss for cracks:

TIME IN SERVICE ON ENGINE MOUNT TIME IN SERVICE BEFORE NEXT INSPECTION 0 to 1,000 hrs. 500 hrs. 1,000 to 2,000 hrs. 200 hrs. 2,000 and above 10 hrs.

Example: Engine mount with 100 hours time in service on effective date of this AD. Inspections required at or before 110, 610, 1110, 1310, 1510, 1710, 1910, 2110, 2120, 2130, etc., hours.

(c) If any crack is detected as a result of any of the inspections conducted in accordance with paragraph (b), before further flight the engine mount, P/N 5002, must be replaced with an uncracked engine mount of the same part number or an engine mount approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(d) The modification and repetitive inspections required by paragraphs (a) and (b) may be discontinued on engine mounts modified in accordance with American Jet Industries Service Bulletin 400-1 dated June 7, 1976, or later FAA-approved revision.

(e) Equivalent inspections or modifications may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(f) Special flight permits may be issued per FAR 21.197 and FAR 21.199 to authorize flight to perform the modification required by paragraph (a), the initial inspection required by paragraph (b), and the modification specified in paragraph (d).

This supersedes amendment 39-2597 (41 F.R. 18647), AD 76-09-08.

This amendment becomes effective August 20, 1976.